Field of the Invention
The invention relates to a liquid preparation, to methods for the production thereof and to the use thereof. The area of application is agriculture and forestry, including horticulture and pomiculture and also the cultivation of ornamental plants, and the establishment and maintenance of lawns. In this regard, the goal of the invention is, in particular, biological plant protection, biological plant strengthening and biological soil improvement.
Description of Related Art
The use of preparations based on the basis of microscopic fungi or other microorganisms allows biological plant protection and thus preventive or curative control of plant disease-causing organisms and harmful organisms on the basis of ecological mechanisms of action directed against said disease-causing and harmful organisms.
Other microorganisms, such as Trichoderma spp., Pythium oligandrum, Bacillus spp., Pseudomonas spp. and Streptomyces spp., are capable of causing reactions in the plants which lead to increased resistance against disease-causing organisms or other stress factors, such as dryness, poor supply of nutrients, unfavorable pH levels or high salt content in the soil.
Yet further microorganisms, such as Trichoderma spp., Penicillium bilaii, Azotobacter spp., Azotomonas spp., Azospirillum spp. and Rhizobium spp., lead to an improvement in nutrient availability in the soil or directly at the plant root.
Such preparations are environmentally friendly and make use of natural regulatory mechanisms which have developed in nature over the course of evolution.
The literature discloses various formulations or preparations in which fungal microorganisms constitute agents in biological plant protection agents, biological plant strengthening agents and biological fertilizers. For instance, microorganisms are formulated as, for example, water-dispersible granules (WG), water-dispersible powders (WP), oil dispersions (OD) or suspension concentrates (SC) (Anonymous, 2005).
The formulation has to ensure that the products have a good shelf life. This means that the microorganisms should be able to retain their vitality for as long as possible even at high temperatures.
The products should have good solubility/dispersibility in water, so that use can be carried out by means of spray application or with the aid of the irrigation system and the microorganisms (e.g., fungal spores or bacterial cells) can be well distributed in the soil, on the plant or on the harmful organism. In this connection, it is particularly important that the microorganisms are not clumped together in aggregates in the aqueous suspension to be used, but instead occur individually (e.g., fungal spores or bacterial cells swimming separately from one another in a suspension). If aggregates occur in the aqueous suspension to be used, this may lead to clogging of the nozzles of the plant protection sprayer or the distribution of the active biological substance in the soil, on the plant or on the harmful organism is inhomogeneous, adversely affecting the action of the product.
Particularly microorganisms which need to be watered into the soil for full development of their action (e.g., for controlling nematodes, soil insects or soil-borne disease-causing organisms) lose their action, since they are already filtered out in the uppermost soil layers by the soil structure if relatively large aggregates are present in the use suspension.
Various microorganisms or organs of microorganisms, more particularly fungal conidia of the genera Beauveria, Isaria, Nomuraea, Metarhizium, Paecilomyces and Penicillium, are water-repellent. In some cases, this property of the microorganisms additionally hampers their use. They can be poorly suspended in water, poorly distributed on the surface of plants or harmful insects, and watered into the soil with difficulty.
The disadvantage of some water-dispersible powders is that the outflow of dusts during their use can be prevented only with difficulty, and so contamination of the user or of the environment can occur.
Because of their formulation, many microbiological preparations contain only a small quantity of their active agent. For instance, there are preparations which contain only 1×107 or 1×108 live fungal conidia per gram. In the case of a minimum application amount which is required for a good action and which is in many cases 1×1011 or 1×1012 and more fungal conidia per hectare, the small active substance concentration in the preparations brings about high costs (costs relating to manufacture, storage, transport and use).
Live microorganisms differ from chemically synthesized active substances with respect to, inter alia, shelf life, since they are not stable in conventional solvents used. If they are exposed to unfavorable conditions, they lose their germination capacity and die. This occurs under prolonged storage, during incubation under relatively high temperatures, upon contact with chemical substances and the like.